Many conventional vehicles utilize friction brakes to slow and/or stop the vehicle. Typically, brake pads may engage a rotor or a drum of a wheel. The energy from the motion of the vehicle is thus lost as heat from surfaces of the brake pads, rotors, and/or drums.
Electric and hybrid-electric vehicles often utilize regenerative braking to recover energy while slowing and/or stopping the vehicle. Typically, an electric motor is coupled to an axle of the vehicle. The electric motor acts as a generator by producing electricity by conversion of the kinetic energy of the vehicle. This electricity may be stored in a battery or immediately used in operating the vehicle. In another configuration, a vehicle may be equipped with a flywheel that is utilized for energy storage.
Typical regenerative braking systems only produce electricity when the vehicle is decelerating. In some conditions, it may be advantageous to produce electricity while the vehicle is accelerating.